Should you worry about cellphone radiation?

Chances are, you have a cellphone within inches of you. Maybe you're reading this story on one or you recently made a call or sent a text.

There are a whopping 6.9 billion mobile phones in the world, according to the World Health Organization. Obviously, we need and depend on our phones, but there's still the nagging question of safety.

Cellphones and cordless phones use radiofrequency radiation (RF) to send signals. Radiofrequency energy is a form of electromagnetic radiation, which can be either ionizing or non-ionizing, reports the National Cancer Institute. Ionizing radiation includes X-rays, which have been proven to be harmful; but the evidence is still iffy on non-ionizing rays.